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silicone use restriction in automotive industries?Helpful Member!(3) 

gelu (Mechanical) (OP)
14 Jan 04 14:22
Hi everybody,
We have a client who developed a protection device made from soft hypoallergenic material mainly from silicone.
The question is if somebody known some things about restriction for the use of silicone content devices in the automotive industries.
All opinions will be very appreciates.
Best regards,
Gelu
Helpful Member!(2)  TVP (Materials)
15 Jan 04 10:29
Silicone, used to be a trademark, but now is a general name for polymers based on polydimethylsiloxane.  Silicone is not listed as a restricted or reportable material by Ford or GM.
sean01 (Automotive)
19 Jan 04 5:09
Gelu,

I have heard that silicone can cause problems if it comes into proximity of paint plants, leading to a painting defect sometimes referred to in slang as 'fish eyes'.

not sure if this helps !!

sean
bart46 (Automotive)
20 Jan 04 11:59
If you are referring to commercial silicone products, these compounds have an adverse effect on paint operations. Most OEM's go to great lengths to keep silicone products well isolated from paint operations.
Helpful Member!  BrendanGay (Chemical)
4 Feb 04 1:18
Silicone products as a general rule are banned from OE sites due to the catastrophically negative effects on painting and adhesives bonding.

Having said this, many forms of silicone are non reactive to painted surfaces, and are OK to be used.

If your client's product is to be fitted in trim, it is potentially OK to be used.

Most OE's will require a paint compatibility test to be done on the material - probably both the encapsulating material and the inner material to ensure that any risks are known.

Your first step would be to check this compatibility, and also perhaps the impact on for example glass bonding adhesives.
Rogerio1 (Chemical)
5 Feb 04 11:06
This probably won't affect you, but there is another area of concern for silicone products: the engine components. Even minute amounts of silicone oils and polymers will burn and produce silica particles, which in turn clog the lambda sensor and shut down catalysts.

In general, there are a few bad low-molecular and very fluid silicone oils which have the tendency over spreading all over the place and contaminating production halls from floor to ceiling. They can disrupt the adhesion of paints, glues or even cause foams to shrink. This is what has made many car manufacturers particularly careful.

But in spite of their undeserved bad reputation, silicones are widely used in the automobile industry - most cars have a few pounds of silicone altogether. The important thing is to make sure that you use a compound with no monomers or volatile components and that your polymer is not reversible, such as LSRs and RTVs (no moisture-cure products!).

Good Luck!
Giacaglia

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